Strip back to brickwork or skim?

[Mbond65]

In the process of transforming a small area into a bathroom.

An external doorway has recently been blocked up and the roof has been replaced, it was leaking which has caused damage to existing plaster.

I’m not sure how to approach making good, the options I’m thinking of:

- Remove all existing plaster, back to brickwork then dot and dab plasterboard

- Remove all existing plaster, then plaster using hardwall then multi finish for finish coat

- Use plastering stabiliser then skim, build up blockwork and water damaged plaster using hardwall then skim

Not sure on the right approach, any advice appreciated please.

Just to provide some more information, this is a 1930s house, the outer walls in this area are single skin.

Thank you

 

[oldbutnotdead]

Unwise using dot and dab pb on a solid external wall (you can get cold damp spots forming on the finished surface due to bridging from the dots).
Since it is an external wall you should consider some insulation.

 

[Mbond65]

Unwise using dot and dab pb on a solid external wall (you can get cold damp spots forming on the finished surface due to bridging from the dots).
Since it is an external wall you should consider some insulation.

Thanks, do you think insulated plasterboard should be used then?

 

[oldbutnotdead]

You can use insulated pb and dot and dab, you could dryline it, choices are many.

 

[foxhole]

Insulated plasterboard fixed with fixing foam.